16446505778 has 8 divisors (see below), whose sum is σ = 24682268268. Its totient is φ = 8219083024.

The previous prime is 16446505771. The next prime is 16446505793. The reversal of 16446505778 is 87750564461.

It can be written as a sum of positive squares in 2 ways, for example, as 15421417489 + 1025088289 = 124183^2 + 32017^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (16446505771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2080001 + ... + 2087892.

Almost surely, 2^16446505778 is an apocalyptic number.

16446505778 is a deficient number, since it is larger than the sum of its proper divisors (8235762490).

16446505778 is a wasteful number, since it uses less digits than its factorization.

16446505778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4169868.

The product of its (nonzero) digits is 5644800, while the sum is 53.

The spelling of 16446505778 in words is "sixteen billion, four hundred forty-six million, five hundred five thousand, seven hundred seventy-eight".